The first major test of public-access defibrillators found that placing the devices in office buildings and shopping malls and training ordinary people to use them can double the chances of surviving cardiac arrest.
Defibrillators have already become standard equipment, like fire extinguishers, in many airports, convention centers and health clubs. And while earlier studies suggest they are safe, there has been no clear proof until now they actually increase survival.
Each year, about 250,000 Americans die from cardiac arrest, which can result from heart attacks, underlying heart disease or accidents, among other causes. While most such deaths happen in the home, roughly 20 percent occur in public places, and 95 percent of victims die even before reaching the hospital.
Paramedics can shock victims' hearts back to a normal beat with defibrillators, but they rarely arrive in time. In fact, every minute spent waiting for a paramedic lowers the chance of survival by 10 percent.
The latest study was intended to see if putting automated defibrillators about the size of laptop computers into the hands of ordinary volunteers increases the chances of saving these people while the ambulance is on the way.
About 1,500 defibrillators were distributed to 993 sports facilities, shopping centers, entertainment venues, community centers, office buildings, factories and schools in Pittsburgh and 23 other cities. In Allegheny County, defibrillators were placed at about 60 locations, including the Gateway Clipper Fleet, Heinz Hall and several hotels and apartment buildings.
About 20,000 volunteers who worked at the sites took part. Half were taught to do CPR only. The rest were also shown how to work defibrillators.
After almost two years, there were 292 attempted resuscitations and 44 survivors -- 29 among the volunteers with defibrillators, and 15 among those who did CPR alone.
Dr. Vince Mosesso, the principal investigator at the University of Pittsburgh, said doubling survival is a tremendous accomplishment.
"The lesson is that having defibrillators onsite and having persons trained to use them and trained to act quickly in an emergency can save lives," Mosesso said.
Results of the study were presented Tuesday at a meeting of the American Heart Association in Orlando, Fla.
Dr. Raymond Gibbons of the Mayo Clinic said he hopes the results will persuade more businesses to install defibrillators.
"It potentially will have an enormous impact," he said. "Hopefully, over time this will save lives."
Epidemiologist Clay Mann of the University of Utah, who headed the project in his state, said the devices seem to be most useful in shopping centers, fitness clubs and other recreation areas where elderly people often congregate.
Most victims in the study were in their 60s and 70s. One disappointment was that while 15 percent of the defibrillators were placed in central locations in apartment buildings and gated communities, they were used in just one save.
The study was sponsored by the National Heart, Lung and Blood Institute with contributions from the heart association and three defibrillator makers.
Staff writer Luis Fábregas contributed to this report.
